JP5923932B2 - Contact switching mechanism and electromagnetic relay - Google Patents

Description

  The present invention relates to a contact opening / closing mechanism and an electromagnetic relay provided with the contact opening / closing mechanism, and more particularly to a power relay.

  Conventionally, as a contact opening / closing mechanism, there is one in which a protruding piece for terminating the extension of an arc is formed on either the left or right side end of a leaf spring provided with a movable contact (see, for example, Patent Document 1).

  However, in the conventional contact opening / closing mechanism, the arc generated between the contacts is extended by a magnetic force and terminated by the projecting piece, but the position of the projecting piece is larger than the distance between the contacts. For this reason, when an arc actually occurs, the end position may not necessarily be a protruding piece.

  In addition, as another contact opening / closing mechanism, an arc runner conductor is provided on the fixed electrode, and a projection is provided on the arc runner conductor, so that an arc generated between the movable electrode contact and the fixed electrode contact at the time of opening can be moved. What is known to be commutated between the tip and the protrusion is known (for example, see Patent Document 2).

  However, in the conventional contact opening / closing mechanism, an arc runner conductor is required as a separate member for the electrode, and another process for providing a projection on the arc runner conductor must be performed. For this reason, there is a problem that the structure is complicated and the cost is increased.

JP 2006-196372 A JP 2010-170876 A

  The present invention provides a contact switching mechanism and an electromagnetic relay capable of quickly extinguishing an arc generated between contacts with a simple and inexpensive configuration without adversely affecting the spring property of the movable contact piece. Is an issue.

As a means for solving the above problems, the present invention provides:
Contact opening / closing mechanism
A fixed contact piece having a fixed contact; a movable contact piece having a movable contact facing the fixed contact so as to be able to contact and separate ; and a pressing portion that presses and operates the movable contact piece .
Each of the contact pieces has a fixed portion fixed to the base, and a main body portion protruding from the base and provided with a contact point.
At least one of the contact pieces includes an extending portion that extends to the contact side provided on the other contact piece,
The extension part is on the opposite side of the fixed part across the contact, and is formed so as to be able to extinguish an arc generated when the contact is opened and closed.
The pressing portion is configured to be disposed on the tip side of the movable contact of the movable contact piece so as to press the opposite surface without projecting to the surface on which the movable contact is provided. It is a thing.

  With this configuration, the arc generated between the contacts can be reliably guided to the extending portion, and can be extinguished quickly. Further, even when the extension portion is damaged when the arc is extinguished, it can be a region unrelated to the conductive portion. Furthermore, if the distance from the conduction region of the contact piece to the tip position of the extended portion is sufficiently large, a structure that is resistant to damage by an arc can be achieved.

  It is preferable that the extension portion has a larger protruding dimension than the contact point protruding from the main body portion.

  With this configuration, the arc generated between the contacts can be more effectively extinguished.

It is preferable that the extending portion is formed so as to be separated from the contact opening / closing position when the contact is opened than when the contact is closed .

  It is preferable to provide a magnet that extends an arc generated between the contact points to the extending portion.

  With this configuration, the arc generated between the contacts can be extended to the extending portion, so that the arc can be more effectively extinguished.

  Further, according to the present invention, as a means for solving the above-described problems, the electromagnetic relay is configured to include the contact opening / closing mechanism described above.

  According to the present invention, since at least one of the contact pieces is formed with the extending portion extending to the contact side provided on the other contact piece, the arc generated between the contacts is reliably extended. It can be extended to a part and can be extinguished quickly.

It is a perspective view of the electromagnetic relay which concerns on this embodiment. It is a perspective view which shows the state which decomposed | disassembled the case and the arc-extinguishing member from FIG. It is a perspective view which shows the state which removed only the case from FIG. FIG. 2 is an exploded perspective view of FIG. 1. It is a disassembled perspective view which shows the state which looked at FIG. 4 from the other side. (A) is a perspective view which shows the state which looked at the base from the upper side, (b) is a perspective view which shows the state which looked at the base from the downward side. It is a disassembled perspective view of the electromagnet block and movable iron piece shown in FIG. It is a disassembled perspective view of the electromagnet block and movable iron piece shown in FIG. It is sectional drawing at the time of contact closing which shows the state which removed the case from FIG. It is sectional drawing at the time of contact opening which shows the state which removed the case from FIG. It is an expansion perspective view of the contact opening-and-closing part of FIG. It is a graph which shows the attraction force curve by the electromagnet block of FIG. 4, and the change of the force which acts on a movable contact piece. It is an expansion perspective view which shows the movable contact piece of FIG. It is the elements on larger scale which show the contact switching mechanism of the electromagnetic relay which concerns on other embodiment.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the following description, terms indicating specific directions and positions (for example, terms including “up”, “down”, “side”, “end”) are used as necessary. Is for facilitating understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms. Further, the following description is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

(1. Overall configuration)
1 to 5 show an electromagnetic relay according to the present embodiment. This electromagnetic relay is generally a base 1 provided with an electromagnet block 2, a contact opening / closing part 3, and a movable iron piece 4 and covered with a case 5. Here, the applied voltage is 400V and the energization amount is 20A. The power relay is used.

(1-1. Base 1)
As shown in FIG. 6, the base 1 is formed in a rectangular shape in plan view by molding a synthetic resin material, and a first mounting portion 6 and a second mounting portion 7 are provided at two locations in the longitudinal direction. (Hereinafter, the direction extending in the longitudinal direction along the long side will be described as the X axis, the direction extending in the short direction along the short side as the Y axis, and the direction extending in the height direction will be described as the Z axis).

  The first mounting portion 6 is for mounting an electromagnet block 2 described later, and is supported in a recess 9 surrounded by a first peripheral wall 8 and a second mounting portion 7 formed on the upper surface of the base 1. A recess 10 is formed. On the bottom surface of the recess 9, a pair of coil terminal holes 11 penetrating the top and bottom surfaces are formed on both sides of the support recess 10 (short direction of the base 1: YY ′ direction).

  A guide portion 12 is formed in the vicinity of the support recess 10 (in the longitudinal direction of the base 1). The guide portion 12 includes a pair of guide walls 13 provided corresponding to the short direction (YY ′ direction) and an insulating wall 14 connecting them. Guide grooves 15 extending in the vertical direction are formed on the opposing surface of the guide wall 13. Both guide grooves 15 guide both side portions of a yoke 41 described later. A guide recess 16 is formed at the center of the region surrounded by the guide wall 13 and the insulating wall 14. A guided portion 50 of a hinge spring 44 described later is located in the guide recess 16.

  The second mounting portion 7 is for mounting the contact opening / closing portion 3, and a pedestal portion 17 having the same height as the first peripheral wall 8 of the first mounting portion 6 is formed. The base portion 17 is formed with a slit-shaped first terminal hole 18 extending in the YY ′ direction. The first terminal hole 18 penetrates only at two communicating portions 19 on both sides on the bottom surface of the base 1, and a movable contact piece 52 described later is press-fitted. A second peripheral wall 20 is formed from three sides of the pedestal portion 17 excluding the first mounting portion side. A portion constituting the X ′ direction side of the second peripheral wall 20 has a large thickness, and a pair of second terminal holes 21 each having a slit shape extending in the YY ′ direction are formed therein.

(1-2. Electromagnet block 2)
As shown in FIGS. 7 and 8, the electromagnet block 2 is obtained by winding a coil 24 around an iron core 22 via a spool 23.

  The iron core 22 is made of a magnetic material in a rod shape, and has a bowl-shaped magnetic pole portion 25 formed at the lower end portion, and a yoke 41 is crimped and fixed at the upper end portion.

  The spool 23 is obtained by molding a synthetic resin material, and has a cylindrical body portion 27 that forms a center hole 26, and flange portions (upper end side flange portion 28 and lower end side flange portion) formed at both upper and lower ends thereof. Part 29).

  The upper end flange 28 has a relief groove 30 formed on the upper surface, and a central hole 26 is opened there. One end of a yoke 41 described later is disposed in the escape groove 30. A central hole 26 is opened in the lower end side flange 29, from which the iron core 22 can be inserted.

  Terminal attachment portions 31 are provided on both side portions of the lower end side flange portion 29, and terminal holding holes 32 are respectively formed therein. A coil terminal 36 to be described later is press-fitted and fixed in each terminal holding hole 32. Step portions 33 are respectively formed on both sides of one end of the terminal attachment portion 31, and coil winding portions 39 of the coil terminals 36 press-fitted and fixed in the terminal holding holes 32 are respectively projected. In addition, a guide groove 34 that extends from the body portion 27 to the side end surface and communicates with the one step portion 33 is formed in the lower end side flange portion 29. One end side (winding start side) of the coil 24 wound around the body portion 27 is disposed in the guide groove 34, and is wound around the coil winding portion 39 of the coil terminal 36 protruding from the step portion 33. . A pair of guide protrusions 35 are provided at a predetermined interval on the bottom surface of the lower end side flange 29. These guide protrusions 35 are positioned in the support recess 10 of the base 1 and serve to position the spool 23, that is, the electromagnet block 2 with respect to the base 1.

  The coil terminal 36 is made of a conductive material in a flat plate shape, and the lower end portion is formed so that the width and thickness gradually decrease as it goes downward. A press-fit portion 37 bulging from one surface is formed by pressing at the upper end portion of the coil terminal 36, and an upper portion thereof is a wide portion 38. A coil winding portion 39 protrudes from one end of the wide portion 38.

  After the coil 24 is wound around the body portion 27 of the spool 23, the insulating sheet 40 is adhered to the outer peripheral surface. One end of the coil 24 is disposed in the guide groove 34 of the spool 23. After winding the spool 23 around the body 27, both ends are wound around the coil winding portions 39 of the respective coil terminals 36, and then soldered. Attached.

A yoke 41 is fastened and fixed to one end of the iron core 22.
The yoke 41 is formed by bending a magnetic material into a substantially L shape. At one end of the yoke 41, an opening 41a for inserting and fixing the one end of the iron core 22 is formed. The other end of the yoke 41 is wide, and protrusions 42 are formed on both sides of the lower end. A movable iron piece 4 which will be described later is located between the projecting portions 42, and one corner portion functions as a fulcrum that rotatably supports the movable iron piece 4. On the outer surface of the intermediate portion of the yoke 41, caulking projections 43 are formed at two locations, upper and lower.

  A hinge spring 44 is caulked and fixed to the intermediate portion of the yoke 41 using the protrusion 43. However, the method of fixing the hinge spring 44 to the yoke 41 is not limited to caulking, and other methods such as ultrasonic welding, resistance welding, and laser welding may be used.

  The hinge spring 44 includes a connection portion 45 that is in surface contact with the outer surface of the intermediate portion of the yoke 41. The connecting portion 45 is formed with through holes 45a at two locations, and the projections 43 of the yoke 41 are inserted and crimped.

(1-3. Contact switching unit 3)
As shown in FIGS. 4 and 5, the contact opening / closing part 3 is composed of a fixed contact piece 51 and a movable contact piece 52 obtained by pressing a conductive material such as copper into a plate shape.

  The fixed contact piece 51 includes a press-fit portion 53, a terminal portion 54 that extends downward from the press-fit portion 53, and a main body portion 55 that extends upward from the press-fit portion 53. The press-fitting portion 53 is formed with a bulging portion 56 that bulges from one side by press working. The bulging portion 56 can be press-fitted into the second terminal hole 21 of the base 1. The terminal portion 54 is narrower than the press-fit portion 53 and is formed so that its position is shifted to one side. The main body portion 55 is formed with a position shifted on the opposite side to the terminal portion 54, and has a width dimension substantially half that of the press-fit portion 53. A through hole is formed in the upper end portion of the main body portion 55, and a fixed contact 57 is fixed by caulking there.

The movable contact piece 52 includes a press-fit portion 58 and a pair of main body portions 59 that extend from both sides of the press-fit portion 58 upward.
Like the fixed contact piece 51, the press-fit portion 58 is formed with a bulging portion 60 extending in the width direction at the center in the vertical direction, and can be press-fit into the first terminal hole 18 of the base 1. A pair of projections 61 projecting downward are formed at both ends of the lower edge of the press-fit portion 58.

  The main body portion 59 is bent and extends in the vicinity of the press-fit portion 58, and a through hole 59a is formed in the upper end portion, and the movable contacts 62 are respectively crimped and fixed thereto. Further, as shown in FIG. 13, an extension part 59 b that bends obliquely upward toward the fixed contact piece 51 side is formed at the upper end part of the main body part 59. The inclination angle of the extending portion 59b with respect to the main body portion 59 is about 140 degrees here. However, the range from about 140 degrees to about 90 degrees can be freely selected. The distal end portion of the extending portion 59 b extends so that the position in the direction perpendicular to the main body portion 59 protrudes from the movable contact 62.

  The movable contact piece 52 can be brought into and out of contact with the fixed contact 57 of the fixed contact piece 51 press-fitted into the second terminal hole 21 while the press-fit portion 58 is press-fitted into the first terminal hole 18 of the base 1. To face. And in this state, as shown in FIG. 10, the front-end | tip part of the extension part 59b has approached the stationary contact 57 side by protruding rather than the movable contact 62 as above-mentioned. Therefore, even if an arc is generated between the contacts, the arc extends to the tip portion of the extending portion 59b and is extinguished early through the extending portion.

(1-4. Movable iron piece 4)
As shown in FIGS. 7 and 8, the movable iron piece 4 is formed by pressing a plate-like magnetic material into a substantially L shape by pressing. One end of the movable iron piece 4 is a sucked portion 63 that is attracted to the magnetic pole portion 25 of the iron core 22. The tip portion and the base portion of the sucked portion 63 are narrow, and interference between the guide protrusion 35 formed on the bottom surface of the spool 23 and the protrusion 42 formed on the lower end portion of the yoke 41 is avoided. . An opening 64 is formed on the other end side of the movable iron piece 4. A hinge spring 44 is inserted through the opening 64 and is in pressure contact with a corner of the sucked portion 63. The other end of the movable iron piece 4 is narrow, and a card member 65 is integrated above the opening 64.

  The card member 65 is made of a synthetic resin material. On one surface where the upper end side of the integrated movable iron piece 4 is exposed, a first protrusion 66 formed on both sides of the upper end portion of the movable iron piece 4 and on the upper side. A second protrusion 67 to be formed is formed. When the attracted portion 63 of the movable iron piece 4 is separated from the magnetic pole portion 25 of the iron core 22, the first projecting portion 66 contacts the yoke 41 after the elastic contact portion 46 of the hinge spring 44 collides with the second projecting portion 67. It is configured as follows. On the other surface of the card, protrusions 68 extending in the vertical direction at predetermined intervals in the width direction are formed. A protruding pressing portion 69 is further formed at the upper end of the protrusion 68 so that the upper end of the main body 59 of the movable contact piece 52 can be pressed. At the lower end of the card member 65, a shielding wall 70 that protrudes from the other surface and extends further downward is formed.

(1-5. Case 5)
As shown in FIG. 2, the case 5 is made of a synthetic resin material in a box shape with an open bottom surface. Sealing holes 71 are formed in the upper corners of the case 5. The sealing hole 71 is thermally sealed after sealing the fitting portion between the base 1 and the case 5. On the upper surface edge of the case 5 (on the side opposite to the sealing hole 71), slit-like recesses 72 are formed on both sides and the center. A recess 73 that is recessed from the upper surface is formed between each of the 72, and a protrusion 74 is formed at the center of the upper surface.

  An arc extinguishing member 75 is attached to the case 5 using the recess 72 and the recess 73.

  The arc extinguishing member 75 includes a pair of permanent magnets 76 arranged at a predetermined interval to extinguish the arc, and a connecting member 77 made of a magnetic material for magnetically connecting the permanent magnets 76. Yes.

  The permanent magnet 76 has a substantially rectangular parallelepiped shape, and is disposed so that the opposing surfaces have different polarities when attached to the inner surfaces of the opposing walls 78 of the connection member 77. However, the polarity of the facing surface may be set so that the direction of the force acting on the arc current is directed to the intermediate wall 79 side of the connecting member 77 described later according to the difference in the direction of current flow between the contacts.

  The connecting member 77 is obtained by bending a plate-like magnetic material by pressing so that both end sides face each other. A permanent magnet 76 is attracted and fixed to the inner surface of each opposing wall 78 by its own magnetic force. The intermediate wall 79 of the connecting member 77 is formed with intermediate protrusions 80 positioned between the opposing walls 78 by cutting both sides from different end sides. Each intermediate projecting portion 80 is located at the center of both opposing walls 78, and plays a role of shortening the magnetic path by projecting between both contact opening / closing positions. That is, the magnetic flux generated from each permanent magnet 76 forms a closed loop with a magnetic circuit that passes through the intermediate wall 79 and each opposing wall 78 via the intermediate protrusion 80 and returns to the permanent magnet 76.

  Thus, according to the arc extinguishing member 75, not only a pair of permanent magnets 76 but also a connection member 77 for magnetically connecting them is provided. For this reason, a magnetic circuit is formed and magnetic flux leakage hardly occurs. Further, by providing the intermediate protrusion 80, the magnetic path can be set short. Therefore, it is possible to increase the magnetic efficiency. As a result, even if an arc is generated at the time of opening and closing the contact, the arc is extended to the side by the Fleming left-hand rule and extinguished in a short time.

(2. Assembly method)
Then, the assembly method of the electromagnetic relay which consists of the said structure is demonstrated.

  The coil 24 is wound around the body portion 27 of the spool 23, and the coil terminal 36 is press-fitted and fixed to the lower end side flange portion 29. Both ends of the coil 24 are wound around the coil winding portion 39 and soldered. Further, the iron core 22 is inserted into the center hole 26 of the spool 23 from the lower end side, and a yoke 41 to which a hinge spring 44 is attached in advance is fixed by caulking to a portion protruding from the upper end. Thereby, the electromagnet block 2 is completed.

  In the completed electromagnet block 2, the movable iron piece 4 is rotatably supported on the lower end portion of the yoke 41 by using a hinge spring 44. In this state, the first protruding portion 66 of the card member 65 integrated with the movable iron piece 4 can come into contact with the yoke 41, and the elastic contact portion 46 of the hinge spring 44 is brought into contact with the second protruding portion 67 of the card member 65. It is possible to contact and separate. Then, the electromagnet block 2 to which the movable iron piece 4 is attached and the contact opening / closing part 3 are mounted on the base 1.

  In mounting the electromagnet block 2, the coil terminal 36 is press-fitted into the coil terminal hole 11 of the base 1, and both side portions of the yoke 41 are inserted into the guide grooves 15 of the guide wall 13. In the mounted state, the guide protrusion 35 is positioned in the support recess 10 and the electromagnet block 2 is positioned in the YY ′ direction. Further, the lower end surface of the projecting portion 42 of the yoke 41 and the bottom surface of the terminal attachment portion 31 are in contact with the bottom surface of the recess 9 of the base 1. Thus, a gap is formed between the bottom surface of the recess 9 of the base 1 and the bottom surface of the lower end side flange portion 29 of the spool 23 so that the movable iron piece 4 can rotate. A shielding wall 70 of the card member 65 integrated with the movable iron piece 4 is disposed beyond the insulating wall 14 of the base 1. At this time, the insulating property between the electromagnet block 2 and the contact opening / closing part 3 is sufficiently secured by the guide wall 13 and the insulating wall 14 of the base 1, the upper part of the card member 65 and the shielding wall 70.

  When the contact opening / closing part 3 is mounted, the press-fitting part 58 of the movable contact piece 52 is press-fitted into the first terminal hole 18 of the base 1. In mounting the movable contact piece 52, the protrusion 61 is positioned at the communication portion 19, so that the mounting state of the movable contact piece 52 can be confirmed from the bottom surface of the base 1. Further, the pressing portion 69 of the card member 65 previously mounted is pressed against the upper end portion of the movable contact piece 52, and the movable iron piece 4 has the attracted portion 63 as a magnetic pole portion of the iron core 22 due to the elastic force of the movable contact piece 52. Positioned at an initial position separated from 25.

  Further, the terminal portion 54 of the fixed contact piece 51 is inserted into the second terminal hole 21 of the base 1, and the press-fit portion 53 is press-fitted and fixed. In this state, the fixed contact piece 51 faces the movable contact piece 52 at a predetermined interval, and the movable contact 62 can be brought into contact with and separated from the fixed contact 57. Further, the distal end portion of the extending portion 59b extending from the upper end portion of the movable contact piece 52 has a fixed contact more than the main body portion 59 in a predetermined region in the direction in which the arc is extended by the permanent magnet 76, as will be described later. It protrudes to the side 51.

  An arc extinguishing member 75 is attached to the case 5. When the arc extinguishing member 75 is attached, the permanent magnet 76 is attached to the opposing wall 78 of the connecting member 77, and the concave wall 72 formed in the case 5 is connected to the opposing wall 78 and the permanent magnet 76 of the connecting member 77. The protrusions 80 are respectively inserted. Then, the case 5 to which the arc extinguishing member 75 is attached is put on the base 1, and the fitting portion between both is sealed.

  The internal space may be sealed by thermally sealing the sealing hole 71. However, the sealing hole 71 can be left open and the internal space can be used in communication with the surrounding atmosphere.

(3. Operation)
Next, the operation of the electromagnetic relay having the above configuration will be described.

  In a state in which the coil 24 is not energized and the electromagnet block 2 is demagnetized, the attracted portion 63 of the iron core 22 is centered on the fulcrum supported by the yoke 41 by the elastic force of the movable contact piece 52. It is located at an initial position away from the magnetic pole part 25. Therefore, the movable contact 62 maintains an open state separated from the fixed contact 57.

  When the coil 24 is energized and the electromagnet block 2 is excited, the movable iron piece 4 is attracted to the attracted portion 63 by the magnetic pole portion 25 of the iron core 22 and resists the urging force of the movable contact piece 52 as shown in FIG. Rotate. As a result, the movable contact piece 52 is elastically deformed, and the movable contact 62 is closed to the fixed contact 57 of the fixed contact piece 51.

  When the energization to the coil 24 is interrupted and the electromagnet block 2 is demagnetized, the movable iron piece 4 loses the attractive force of the iron core 22 and rotates by the elastic force of the movable contact piece 52. At this time, first, the second projecting portion 67 formed on the card member 65 of the movable iron piece 4 collides with the elastic contact portion 46 of the hinge spring 44. The second protrusion 67 is made of synthetic resin, and the elastic contact portion 46 is elastically deformed. And the contact state of the 2nd protrusion part 67 and the elastic contact part 46 is obtained early after the movable iron piece 4 starts rotation. Therefore, the collision sound hardly occurs. The first protrusion 66 made of synthetic resin contacts the intermediate portion of the yoke 41 while the movable contact piece 4 is further rotated to elastically deform the elastic contact portion 46. For this reason, the rotational speed of the movable iron piece 4 is reduced, and the generation of the collision sound is sufficiently suppressed here. As described above, the movable iron piece 4 smoothly returns to the initial position without generating a collision sound, and the movable contact 62 is separated from the fixed contact 57 and located at the open position.

  By the way, when the contact is opened, an arc may be generated between the contacts. In this case, an arc extinguishing member 75 is disposed around the contact opening / closing region, and an extending portion 59 b is formed at the upper end portion of the movable contact piece 52. For this reason, the generated arc is quickly extinguished.

  That is, the magnetic flux generated from the N pole of each permanent magnet 76 passes through the intermediate wall 79 via the intermediate protrusion 80 of the connecting member 77, and returns to the S pole of each permanent magnet 76 from the opposing wall 78. Flowing. Each magnetic circuit constitutes a closed loop, and there is almost no magnetic flux leakage to the surroundings. The presence of the intermediate protrusion 80 can effectively apply a magnetic force to the contact open / close position, that is, the arc generated between the contacts. As a result, according to Fleming's left-hand rule, a force acts on the generated arc in a direction (upward) perpendicular to the contact opening direction, and this arc is greatly extended. In addition, in the direction in which the arc is extended, the distal end portion of the extending portion 59b formed at the upper end portion of the movable contact piece 52 is located. Therefore, the generated arc reaches the tip portion of the extending portion which is the closest position, and is rapidly extinguished.

The operating voltage of the electromagnet block 2 can be adjusted as follows.
That is, the operating voltage of the electromagnet block 2 can be suppressed by changing the inclination angle of the elastic contact portion 46 of the hinge spring 44. Specifically, when the inclination angle of the elastic contact portion 46 with respect to the yoke 41 is increased, the magnetic field generated from the magnetic pole portion 25 of the iron core 22 acts on the attracted portion 63 of the movable iron piece 4 as shown in the graph of FIG. The position of the operating point can be changed with respect to a change in force (suction force curve). That is, by increasing the inclination angle of the elastic contact portion 46, it is possible to suppress the force required until the elastic contact portion 46 contacts the first protrusion 66 after the contact is opened. As a result, the operating voltage of the electromagnet block 2 can be suppressed so that the attractive force curve changes at a position smaller than that shown in the figure.

  In addition, this invention is not limited to the structure described in the said embodiment, A various change is possible.

  In the above-described embodiment, the extending portion 59b is formed at the upper end portion of the movable contact piece 52. However, it may be formed at the upper end portion of the fixed contact piece 51, or the movable contact piece 52 and the fixed contact piece. 51 may be formed on both. However, when forming both, care must be taken in the positional relationship so that the extending portions do not short-circuit. For example, it is possible to cope with the positional relationship of the extending portions by shifting the position in the longitudinal direction of the main body portion.

  In the above embodiment, the extending portion 59b is configured to form an angle of about 140 degrees with respect to the main body portion 59, but can be freely set up to about 90 degrees, as shown in FIG. Thus, it is most preferable that the angle is about 90 degrees. If the angle is larger than about 140 degrees, the projecting dimension in the direction perpendicular to the main body 59 is larger than that of the movable contact 62, so that the length of the extending portion 59b becomes too large. On the other hand, if the angle is smaller than about 90 degrees, there is a risk of short-circuiting due to too close to each contact. Therefore, the angle formed by the extending portion 59b with respect to the main body portion 59 is set in a range of about 90 degrees to about 140 degrees.

  The contact opening / closing mechanism according to the present invention can be similarly employed as long as it is not only an electromagnetic relay but also an electrical device having a mechanism such as a switch that opens and closes a contact and generates an arc between the contacts.

DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Electromagnet block 3 ... Contact opening / closing part 4 ... Movable iron piece 5 ... Case 6 ... 1st mounting part 7 ... 2nd mounting part 8 ... 1st peripheral wall 9 ... Recess 10 ... Supporting recessed part 11 ... Coil terminal hole DESCRIPTION OF SYMBOLS 12 ... Guide part 13 ... Guide wall 14 ... Insulating wall 15 ... Guide groove 16 ... Guide recessed part 17 ... Base part 18 ... 1st terminal hole 19 ... Communication part 20 ... 2nd peripheral wall 21 ... 2nd terminal hole 22 ... Iron core 23 ... Spool 24 ... Coil 25 ... Magnetic pole part 26 ... Center hole 27 ... Body part 28 ... Upper end flange 29 ... Lower end flange 30 ... Escape groove 31 ... Terminal mounting part 32 ... Terminal holding hole 33 ... Step part 34 ... Guide Groove 35 ... Guide protrusion 36 ... Coil terminal 37 ... Press fit part 38 ... Wide part 39 ... Coil winding part 40 ... Insulating sheet 41 ... Yoke 42 ... Protrusion part 43 ... Protrusion 44 ... Hinge spring 45 ... Connection part 46 ... Elastic contact Part 47 ... 1st Inclined portion 48 ... second inclined portion 49 ... elastic support portion 50 ... guided portion 51 ... fixed contact piece 52 ... movable contact piece 53 ... press-fit portion 54 ... terminal portion 55 ... main body portion 56 ... bulge portion 57 ... fixed contact 58 ... Press-fit part 59 ... Main body part 59a ... Through hole 59b ... Extending part 60 ... Expanded part 61 ... Protrusion 62 ... Movable contact 63 ... Suction part 64 ... Opening part 65 ... Card member 66 ... First projecting part 67 ... First 2 Protruding part 68 ... Projection part 69 ... Pressing part 70 ... Shielding wall 71 ... Sealing hole 72 ... Slit 73 ... Recess 74 ... Projection 75 ... Arc extinguishing member 76 ... Permanent magnet 77 ... Connection member 78 ... Opposing wall 79 ... intermediate wall 80 ... intermediate protrusion

Claims (6)

A fixed contact piece having a fixed contact; a movable contact piece having a movable contact facing the fixed contact so as to be able to contact and separate; and a pressing portion that presses and operates the movable contact piece.
Each of the contact pieces has a fixed portion fixed to the base, and a main body portion protruding from the base and provided with a contact point.
At least one of the contact pieces includes an extending portion that extends to the contact side provided on the other contact piece,
The extension part is on the opposite side of the fixed part across the contact, and is formed so as to be able to extinguish an arc generated when the contact is opened and closed.
The pressing portion is disposed on the tip side of the movable contact of the movable contact piece so as to press the opposite surface without projecting to the surface side where the movable contact is provided. Contact opening and closing mechanism.   The contact opening / closing mechanism according to claim 1, wherein the extension portion has a protruding dimension larger than that of the contact protruding from the main body portion.   3. The contact opening / closing mechanism according to claim 1, wherein the extending portion is formed so as to be separated from the contact opening / closing position when the contact is opened rather than when the contact is closed. The extending portion is formed in the body portion, the contact switching mechanism according to claim 3, characterized in that it consists site bent substantially at right angles to the body portion.   5. The contact opening / closing mechanism according to claim 1, further comprising a magnet that extends an arc generated between the contacts to the extending portion. 6.   An electromagnetic relay comprising the contact switching mechanism according to any one of claims 1 to 5.